You're correct, there are two functions in Exchange which were written by the team at Shopp, and if you bothered to look at the code you're referencing you'd see that it is, in fact, attributed immediately before the function. By honest mistake, we actually only attributed one of those functions, but we've corrected the issue and credited both to him. We did not try to hide these attributions or our use of the GPL code. In fact, we went out of our way to reference any GPL authors whose code we used and modified. A clear example can be seen in our db session code.

I appreciate your concern, and because of your post we were able to attribute an additional function that we honestly missed. Our intention was not to misrepresent ourselves or our plugin. But this is clearly not a GPL violation as you've claimed. If you have any further questions, please let us know.

Thanks for the quick response. It a refresh change for some transparency in these support forums.

I definitely looked at the code and the functions.php was the spot I found the error. I think its also worth mentioning that the whole structure of the API system, not the code specifically, was also clearly sourced from Shopp including the API call syntax and file structure, but as you pointed out above that is not a GPL Violation.

However, given that information above do you think it would be prudent to list Jonathan Davis from Shopp as a contributor in the plugin repo?

I appreciate your concern, but I've already spoken to Jonathan at Shopp. We've done our best to be transparent here as well as in our code. I think we've gone above and beyond in attributing where attribution is called for.

There is no real issue here, so I don't see any reason to continue this thread.